Lisi, Does the flashplugin-nonfree package in Jessie not work for you? It is a plugin for Iceweasel/Firefox. Or do you need something else?
See also: https://wiki.debian.org/FlashPlayer/ - Nate -- "The optimist proclaims that we live in the best of all possible worlds. The pessimist fears this is true." Ham radio, Linux, bikes, and more: http://www.n0nb.us